Antipsychotic Use by Newly Diagnosed Patients Drops After FDA Warnings

The use of antipsychotics by people with early Parkinson’s disease (PD) has fallen substantially since the U.S. Food and Drug Administration (FDA) issued warnings about treating dementia with these medications, according to a database study of patients in Wales.

Black-box warnings, which indicate a risk of death or serious injury with a medication’s use, were placed by the agency on antipsychotics for dementia patients in 2005, and again in 2008, after clinical trials found that elderly patients using them were more likely to die than those who were not.

The database study, “Trends and Contributing Factors for Prescribing Antipsychotics in Newly Diagnosed Parkinson’s Disease Patients: A Population-Based Study,” was published in Risk Management and Healthcare Policy.

Psychosis, which includes hallucinations (seeing or hearing things that are not there) and/or delusions (fixed beliefs that are not based in reality) can be common in Parkinson’s, typically more so in later stages of the disease. But some with early Parkinson’s also experience this symptom.

Antipsychotics, as the name suggests, are a class of medications that can be used to treat psychosis. However, the use of these medicines in people with Parkinson’s is complex, because some antipsychotics can exacerbate Parkinson’s motor symptoms, including dyskinesia (uncontrolled and involuntary movements).

A researcher at King Khalid University in Saudi Arabia performed an analysis aiming to understand the factors that have affected antipsychotic use in recent years among people newly diagnosed with Parkinson’s.

Using a Welsh database, Khalid Orayj, PhD, analyzed information covering 9,142 people with Parkinson’s (58.6% male, mean age of 73.7) who were diagnosed between 2000 and 2016.

His analysis was restricted to prescriptions given to people within one year of a Parkinson’s diagnosis to treat psychosis; all were not using antipsychotics in the year before their diagnosis.

In total, 1,994 of these newly diagnosed patients (21.8%) developed psychosis, and just over half (1,095 or 55%) were subsequently prescribed antipsychotics. The most commonly prescribed antipsychotic was quetiapine (sold under the brand name Seroquel, among others), given to 49% of these people.

Using statistical models, Orayj assessed factors that were associated with antipsychotic use. Age had a significant impact: patients between 61 and 80 years old were about 44% more likely to be prescribed antipsychotics than those ages 40 to 60.

Timeframe was another significant factor. Patients diagnosed between 2009 and 2016 were significantly less likely to be prescribed antipsychotics, compared with those diagnosed between 2000 and 2008. Notably, no such change was seen in dementia medications used to treat psychosis.

“A substantial decrease in antipsychotic prescribing patterns was found after the FDA issued its warnings against the use of antipsychotics in dementia patients [in 2005 and 2008],” Orayj wrote.

“Dementia is strongly associated with psychosis in PD [Parkinson’s disease],” Orayj added. “Therefore, it was expected that the FDA warning would decrease the use of antipsychotics in PD patients.”

Consistent with the link between psychosis and dementia in Parkinson’s, patients with a history of dementia were over three times more likely to use antipsychotics than those without that history.

Individuals with a previous heart attack or stomach ulcer also were statistically more likely to have been prescribed antipsychotics. Orayj suggested this is because some antipsychotics can increase the risk of these comorbidities, and he noted a need for more research.

“This study found a substantial decrease in antipsychotic prescribing patterns after the FDA issued warnings in 2005 and 2008 against the use of antipsychotics, showing a reasonable adherence to national and international prescribing guidance,” Orayj concluded. “Continuous and closer monitoring of antipsychotic use is warranted, which must be balanced with the effective and safe use of antipsychotics in PD patients.”